Cutting tables for cutting a workpiece such as a metal plate typically include a table surface for supporting the workpiece. A cutting torch assembly, which may include a plasma cutting torch, a laser cutting torch, or the like, may he suspended above the cutting table for cutting the metal plate. In some instances, the cutting torch may be utilized for repeatedly cutting the metal plate in an automated sequence, in order to follow a predetermined pattern or template.
Cutting the metal plate supported on the cutting table with the cutting torch may generate undesirable fumes, including smoke, as well as generating slag, which may accumulate under the cutting table. Water cutting tables have been provided which attempt to solve this problem by cutting a workpiece underwater. However, such tables may leave water spotting on bright finishes and create the risk of hydrogen entrapment when cutting an aluminum workpiece. Further, immersion of a workpiece may tend to cause the workpiece to rust. Another disadvantage of water cutting tables is the need to dispose of water potentially including contaminants after the cutting operation has been completed.
Downdraft cutting table assemblies, such as the cutting tables disclosed in U.S. Pat. Nos. 6,039,915 and 6,165,410, have been provided for removing undesirable fumes and slag from the vicinity of the cutting table by utilizing one or more exhaust ducts for evacuating the fumes, and a slag removal system for removing slag. Previously, such cutting tables have utilized pneumatically actuated venting systems. While these systems work well, they are complex and require pneumatic controllers to ensure proper actuation.
Consequently, it would he desirable to provide a door assembly for a downdraft cutting table assembly, such door assembly being mechanically actuated by the cutting torch assembly as it positions the cutting torch over the cutting table.